This invention relates to a swash-plate type compressor, and more particularly to a simple lubricant oil pumping system which is provided within a compressor of this type for supplying lubricant oil to thrust bearings, radial bearings and other sliding machine parts of the compressor.
Many air conditioning systems employ swash-plate type compressors for compressing refrigerant gas. According to a typical swash-plate type compressor, a swash plate is arranged within a cylinder block and secured on a drive shaft extending through the cylinder block. Rotation of the swash plate causes reciprocating motions of pistons within their respective cylinder bores to carry out refrigerant gas compressing actions in cooperation with suction valves and discharge valves provided on valve plates mounted at the opposite ends of the cylinder block. The lubricant oil feeding system employed in such type compressor conventionally includes a type using a gear pump, such as a trochoidal type. The gear pump is arranged within the compressor in such a manner that an inner gear is secured on an end of the drive shaft of the compressor and meshes with an outer gear mounted in the cylinder head of the compressor, the inner and outer gears being rotatable in unison with rotation of the drive shaft to suck lubricant oil stored in the bottom of the cylinder block. The lubricant oil feeding system of this type is capable of supplying lubricant oil to required places in the compressor at a sufficient rate and with high stability.
However, the gear pump is rather expensive and requires large power to drive. Further, it is hard to mount in the compressor. That is, first the inner gear has to be rigidly mounted onto the drive shaft, and then the outer gear mounted into the cylinder head so as to mesh with the inner gear. Still further, metallic powder can be produced due to the meshing engagement of the inner and outer gears and entrained into the lubricant oil.